How severe is CVE-2021-27698?

CVE-2021-27698 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27698 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27698?

CVE-2021-27698 affects Riot-os Riot. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27698?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-27698 published?

CVE-2021-27698 was published on 2021-04-06 and last updated on 2026-06-17.

CVE-2021-27698

CVE-2021-27698 is a critical-severity vulnerability in Riot-os Riot with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Riot-os Riot
Published: 2021-04-06
Last modified: 2026-06-17

Description

RIOT-OS 2021.01 contains a buffer overflow vulnerability in /sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c through the _parse_options() function.

Frequently asked questions

What is CVE-2021-27698?: RIOT-OS 2021.01 contains a buffer overflow vulnerability in /sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c through the _parse_options() function.
How severe is CVE-2021-27698?: CVE-2021-27698 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27698 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27698?: CVE-2021-27698 affects Riot-os Riot. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27698?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-27698 published?: CVE-2021-27698 was published on 2021-04-06 and last updated on 2026-06-17.

References

https://github.com/RIOT-OS/RIOT/issues/16085

Affected products (1)

cpe:2.3:o:riot-os:riot:2021.01:*:*:*:*:*:*:*

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